Question: $\dfrac{7}{10} - \dfrac{4}{6} = {?}$
Answer: $ = {\dfrac{7 \times 3}{10 \times 3}} - {\dfrac{4 \times 5}{6 \times 5}} $ $ = {\dfrac{21}{30}} - {\dfrac{20}{30}} $ $ = \dfrac{{21} - {20}}{30} $ $ = \dfrac{1}{30}$